Cooling Your Home Efficiently


Closing blinds and shades on hot summer days will help keep your house cool.

Although your first thought for cooling may be air conditioning, there are many alternatives that provide cooling with less energy use. A combination of proper insulation, energy-efficient windows and doors, daylighting, shading, and natural ventilation will keep homes cool in most climates. Although natural ventilation should be avoided in hot, humid climates, the other approaches can significantly reduce the need to use air conditioning. For more about such approaches to keeping your home cool, see the EREC fact sheet, Cooling Your Home Naturally.

In climates with cool, dry summer nights, nighttime ventilation can reduce or eliminate the need for air conditioning during the day. Window fans or a whole-house fan provide effective means of exhausting the day's hot air during the night. See the fact sheet, Cooling Your Home with Fans and Ventilation. However, whole-house fans can cause large heat losses during the winter, so their openings should be well insulated during the heating season. See the fact sheet, Installing and Using a Whole-House Fan. In all climates, windows and shades should be kept shut during hot days to keep out the hot air and to block the warming effects of the sunshine.

Evaporative coolers (also called swamp coolers) are effective in hot, arid climates. As the name implies, these coolers chill the air by evaporating water into it. Because the evaporating water provides a natural cooling effect, evaporative coolers use much less energy than standard air conditioners. Evaporative coolers need to be covered and insulated during the heating season.

If you must use air conditioning, a central air conditioning system will cool your house more efficiently than room conditioners. However, if you only need to cool a small portion of your house (for instance, your bedroom), a room air conditioner may be the best choice. Choose a central air conditioner with a high seasonal energy efficiency ratio (SEER). Room air conditioners are labeled with their energy efficiency ratio (EER); choose a unit with a high EER.